Question

我正在创建一个应用程序，在DataTemplate中，在WPF的ListBox中有一个TextBox元素。我想按名称访问TextBox元素以便编辑，或直接从C＃代码中读取值，请帮忙。在WPF应用程序中添加了多个TextBox，因此我如何按索引对它们进行排序？

<ListBox x:Name="listBox" HorizontalAlignment="Left" Height="336" Margin="276,69,0,0" VerticalAlignment="Top" Width="242" SelectionChanged="listBox_SelectionChanged">
        Grid.IsSharedSizeScope="True"
        HorizontalContentAlignment="Stretch">
        <ListBox.ItemTemplate>
            <DataTemplate x:Name="D_Template">
                <Grid Margin="4" Width="222">
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="Auto" SharedSizeGroup="Key" />
                        <ColumnDefinition Width="*" />
                    </Grid.ColumnDefinitions>
                    <TextBox x:Name ="TextValue" Grid.Column="1" Text="{Binding Value}" />
                </Grid>
            </DataTemplate>
        </ListBox.ItemTemplate>
    </ListBox>

如您所见，ListBox的变量名称为“listBox”，DataTemplate已分配给“D_Template”，TextBox分配给名称“TextValue”。感谢您的帮助，谢谢您的时间。：）

Answer 1

你应该将listbox itemssource绑定到一个对象集合并读取/更改它而不是直接访问文本框。但是如果由于某种原因你不能或不想这样做，这段代码可以帮到你。（请注意，我真的不鼓励这个解决方案）

    private void Button_Click(object sender, RoutedEventArgs e)
    {   //pretend you want to access the second item
        object myItem = myListbox.Items[1];
        ListBoxItem container = myListbox.ItemContainerGenerator.ContainerFromItem(myItem) as ListBoxItem;
        ContentPresenter contentPresenter = FindVisualChild<ContentPresenter>(container);
        DataTemplate myDataTemplate = contentPresenter.ContentTemplate;
        TextBox myTextbox = myDataTemplate.FindName("myTextbox", contentPresenter)as TextBox;
        if (myTextbox != null)
        {
            myTextbox.Text = "text changed!";
        }
    }

    public static IEnumerable<T> FindVisualChildren<T>(DependencyObject depObj) where T : DependencyObject
    {
        if (depObj != null)
        {
            for (int i = 0; i < VisualTreeHelper.GetChildrenCount(depObj); i++)
            {
                DependencyObject child = VisualTreeHelper.GetChild(depObj, i);
                if (child != null && child is T)
                {
                    yield return (T)child;
                }

                foreach (T childOfChild in FindVisualChildren<T>(child))
                {
                    yield return childOfChild;
                }
            }
        }
    }

    public static childItem FindVisualChild<childItem>(DependencyObject obj)
        where childItem : DependencyObject
    {
        foreach (childItem child in FindVisualChildren<childItem>(obj))
        {
            return child;
        }

        return null;
    }

在C＃中访问嵌套的XAML控件

1 个答案: